25 



rocks lying hidden under the New Red Sandstones of the Midlands. 

 This latter view he afterwards extended by showing that the 

 Halesowen Conglomerates (Carboniferous) contained fragments 

 denuded from the higher rocks of such an area, the Permian Con- 

 glomerates, fragments from beds lower down in the series, and 

 the Permian Breccias, masses broken from the lowest rock-stumps, 

 made of the oldest rocks left when denudation had cut down very 

 deeply. 



Simultaneously the Nuneaton work proceeded. The relation 

 between the pre-Cambrian Caldecote rocks and the (Cambrian) 

 Quartzites, at first inferred from conglomerates in the quartzites, 

 was demonstrated in actual sections, the quartzite was sub-divided, 

 beds of ' fucoid ' type were found in it, middle as well as upper 

 Cambrian fossils were discovered in the Stockingford Shales, the 

 unconformable junction of the Carboniferous basement was revealed 

 in open section, and at last the famous Hyolithes limestone with its 

 fossils was discovered near the summit of the Quartzite, the dis- 

 covery being based on observations communicated by Dr. T. Stacey 

 Wilson in 1895, and announced in 1897. 



2. The Shropshire Ordovician. 



This work, however, slowly developed itself between the years 

 1881 and 1897. Meanwhile he had other irons in the fire. He 

 had already before 1879 visited the Shelve district of Shropshire, 

 but in 1885 he took up vigorously the work of mapping, and invited 

 the writer to make a study of the igneous rocks of that district 

 in his company. The first outcome of this work was communicated 

 to the British Association at its meeting in Birmingham in 1886.* 

 The stratigraphy turned out to be simple in comparison with that 

 of South Scotland, and the succession proved to be complete from 

 the base of the Arenig (Skiddavian) rocks to a level high up in the 

 Bala (Caradocian). Many of the graptolite horizons established 

 elsewhere were recognised, together with interbedded faunas of 

 trilobites and shells. At the same time Lapworth took great 

 interest in the igneous rocks, mapped them carefully, and made 

 many valuable suggestions, several of which proved valid on the 

 ground, as to the relations of these rocks to the sediments and as 

 to their genetic relations among themselves. For example, from 

 his preliminary work, and from his study of the Geological Survey 

 map, he anticipated that the intrusive rocks would be laccolitic in 

 form, as turned out to be the case. 



He next extended his researches to the Caradoc country on 

 the eastern side of the Longmynd, and soon satisfied himself that 

 the main sedimentary series there rested unconformably on older 



* 40. 



